The invention relates to an air intake device, particularly an intake manifold for an internal combustion engine, having a ram manifold with intake ducts as ram pipes to utilize ram charging effects and longitudinally adjustable resonance channels and a resonance manifold to utilize resonance charging effects. The invention further relates to a control housing for accommodating the longitudinally adjustable resonance pipes.
The use of the described effects of resonance and ram charging is known and is simultaneously implemented in an air intake device described in published German Patent Application No. DE 39 40 486 A1. The function of such an air intake device can, for example, be discerned based on FIG. 2 of said document. The resonance manifold is accommodated in a hollow cylinder 22 and provided with an inlet for the combustion air. Via orifices 8a, 8b the air reaches a resonance channel 8 that is longitudinally adjustable by rotating the cylinder 22. The resonance channel opens out into a ram manifold 6 through which the combustion air reaches intake ports 2, which open out through a cylinder head flange 4 for connection with the internal combustion engine. Arranged parallel to the ram manifold 6 is a ram manifold 7, which operates analogously to ram manifold 6. The two ram manifolds are interconnected in a manner not shown via a port that can be closed by a resonance valve. When the resonance valve is closed, the effect of resonance charging the internal combustion engine with combustion air is used, whereas when the flap is open the ram charging effect is used.
This technical solution disclosed for the intake manifold of this German patent document is very compact in its design in that the housing areas of the resonance channels and the intake manifold comprising the ram manifolds 6, 7 and the intake ducts 2, 3 are nested within one another. The entire air intake device, due to the required minimum radii of the ports through which the combustion air flows, nevertheless requires an overall volume that is rarely available in the application shown, which is an internal combustion engine with V-shaped cylinder arrangement. The air intake device is further characterized by a considerable overall height so that, even if the air intake device can be installed in the internal combustion engine, its total height is difficult to accommodate in the engine compartment of a vehicle.
Thus, it is the object of the invention to provide an air intake system with intake ducts and longitudinally adjustable resonance channels, which can be optimally adapted to the geometric boundary conditions of the available installation space.
This and other objects are achieved in accordance with the present invention by the apparatus described and claimed hereinafter.
The air intake device according to the invention has longitudinally adjustable resonance channels that extend helically around at least one resonance manifold. The resonance channels can also wind around two different resonance manifolds, in which case the resonance manifolds must communicate with one another via a line in order to ensure the effect of resonance charging. A manifold in the sense of the invention is defined as an acoustically effective volume. Thus, to be exact, the acoustically effective connection between the two resonance manifolds also forms part of the volume that produces the resonance effects. The length of the resonance channels is determined by rotating one or more control elements that are either combined in a control housing or are accommodated in different control housings. The control element contains the resonance manifold in its central area so that the connection opening between resonance manifold and resonance channels can be shifted by rotating the control element. As a result, the effective length of the resonance channels is variable.
The intake ducts can be assigned to two groups and accordingly lead to outlets in at least one cylinder head flange. It is conceivable to provide an intake manifold for an internal combustion engine with inline cylinder arrangement. Here, the two groups of cylinders converge in one cylinder head flange. The intake manifold, however, can also be conceived for an internal combustion engine with a V-type cylinder arrangement, in which the groups of intake ducts with the associated outlets are each provided for a respective cylinder bank. In principle, it is feasible to divide the intake ducts into three different groups, for example, for a combustion engine with a W-type cylinder arrangement.
At least one resonance channel must be provided per ram manifold. It is also possible, however, to arrange a plurality of resonance channels, so that the necessary cross-sectional area for the resonance channels can be better adapted to the geometric boundary conditions of the air intake device. Closing off a portion of the resonance channels makes it possible to reduce the total cross-sectional area of the resonance channels. The resonance valve between the ram manifolds can be arranged in a duct that interconnects the different ram manifolds. Another option is to arrange the resonance flaps in a partition between the ram manifolds. This makes it possible to achieve a higher level of integration of the individual volumes in a housing structure. The control housings, too, can be integrated in the housing structure of the air intake device.
The invention is characterized by a connecting duct that extends between the resonance channels and the ram manifolds and contributes to bridging a spatial distance resulting between the ram manifolds and the substantially cylindrical volume of the control housing. This obviates the necessity for a complex integration of the individual components into a housing structure of the air intake device as described in DE 39 40 486. The connecting ducts provide grater design latitude in the arrangement of the control housing. As a result, the geometry of the intake manifold can be optimally adapted to the planned overall volume. The connecting ducts extend the longitudinally adjustable resonance channels and consequently have a resonance effect. In the design of the air intake device, attention must therefore be paid to the required longitudinal ratios and the required control range through the adjustment of the length. Within these boundary conditions, the geometry of the connecting ducts can be freely designed.
According to an advantageous embodiment of the invention, a plurality of resonance channels is integrated into a single housing. This reduces the component cost for the resonance channel adjustment and results in a compact control housing. In the most favorable case, two resonance channels are provided for the air intake device, which are arranged side by side in a drum-shaped control housing. The air intake is located, for example, in the axis of rotation for the control elements, and the connecting ducts are tangentially adjacent to the outer circumference of the control housing. Through a corresponding curvature of the connecting ducts, the air can also be redirected within the resonance channels and guided to the corresponding inlets in the ram manifolds.
According to a further embodiment of the invention, the resonance channels are arranged offset around the resonance manifold. As a result the connecting ducts can have different lengths, so that the overall length of the resonance channels is equal, irrespective of the position of the control elements. This further enhances the design freedom in the arrangement of the control housing within the air intake device.
In accordance with a further embodiment of the invention, a plurality of resonance channels is combined in one control element. This makes it possible further to reduce the component cost, so that the assembly can be produced more economically.
It is advantageous if the connecting ducts are combined in a multi-chamber profile. This multi-chamber profile forms a separate cross section for each of the connecting ducts. The fact that certain wall portions can be used by each of the connecting ducts makes it possible to save material overall. Furthermore, if the multi-chamber manifold is connected with other housing structures of the air intake device, the assembly costs may be reduced.
In accordance with a further embodiment of the invention, the control housing is configured separately from an intake manifold housing. The two housings together create the air intake device, and the intake manifold housing comprises at least the ram manifolds and the intake ducts. The connection between intake manifold housing and control housing is ensured at least by the connecting ducts. In addition, other assembly devices may be provided, which result in a more rigid connection and facilitate assembly. If the control housing is designed separately, it can advantageously be used as a module that is suitable for mounting to different intake manifolds. Thus, the control housing can be adapted to different intake manifolds, so that the cost of a new design is limited to the intake manifold housing. This makes it possible to develop design series and equip different engine types with intake manifolds that are provided as a function of the equipment, with or without resonance charging.
According to a further embodiment of the invention, the connecting ducts of the control housing can be designed at least in part as adapter elements to permit adaptation to different intake manifolds. This allows for a geometric adaptation to different intake manifold housings by using different adapter elements.
A particularly simple option is to mount the control housing to the throttle connection of the intake manifold housing. The throttle is then no longer mounted to the intake manifold housing but to the combustion air intake on the control housing. This also makes it possible to retrofit resonance charging to existing intake manifold concepts, which provide for aggregation of a modular throttle on the inlet connection of the intake manifold.
These and other features of preferred embodiments of the invention, in addition to being set forth in the claims, are also disclosed in the specification and/or the drawings, and the individual features each may be implemented in embodiments of the invention either individually or in the form of subcombinations of two or more features and can be applied to other fields of use and may constitute advantageous, separately protectable constructions for which protection is also claimed.